block/curl.c

   1 /*
   2  * QEMU Block driver for CURL images
   3  *
   4  * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "qemu/osdep.h"
  25 #include "qapi/error.h"
  26 #include "qemu-common.h"
  27 #include "qemu/error-report.h"
  28 #include "block/block_int.h"
  29 #include "qapi/qmp/qbool.h"
  30 #include "qapi/qmp/qstring.h"
  31 #include "crypto/secret.h"
  32 #include <curl/curl.h>
  33 #include "qemu/cutils.h"
  34
  35 // #define DEBUG_CURL
  36 // #define DEBUG_VERBOSE
  37
  38 #ifdef DEBUG_CURL
  39 #define DEBUG_CURL_PRINT 1
  40 #else
  41 #define DEBUG_CURL_PRINT 0
  42 #endif
  43 #define DPRINTF(fmt, ...)                                            \
  44     do {                                                             \
  45         if (DEBUG_CURL_PRINT) {                                      \
  46             fprintf(stderr, fmt, ## __VA_ARGS__);                    \
  47         }                                                            \
  48     } while (0)
  49
  50 #if LIBCURL_VERSION_NUM >= 0x071000
  51 /* The multi interface timer callback was introduced in 7.16.0 */
  52 #define NEED_CURL_TIMER_CALLBACK
  53 #define HAVE_SOCKET_ACTION
  54 #endif
  55
  56 #ifndef HAVE_SOCKET_ACTION
  57 /* If curl_multi_socket_action isn't available, define it statically here in
  58  * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
  59  * less efficient but still safe. */
  60 static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
  61                                             curl_socket_t sockfd,
  62                                             int ev_bitmask,
  63                                             int *running_handles)
  64 {
  65     return curl_multi_socket(multi_handle, sockfd, running_handles);
  66 }
  67 #define curl_multi_socket_action __curl_multi_socket_action
  68 #endif
  69
  70 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
  71                    CURLPROTO_FTP | CURLPROTO_FTPS)
  72
  73 #define CURL_NUM_STATES 8
  74 #define CURL_NUM_ACB    8
  75 #define READ_AHEAD_DEFAULT (256 * 1024)
  76 #define CURL_TIMEOUT_DEFAULT 5
  77 #define CURL_TIMEOUT_MAX 10000
  78
  79 #define FIND_RET_NONE   0
  80 #define FIND_RET_OK     1
  81 #define FIND_RET_WAIT   2
  82
  83 #define CURL_BLOCK_OPT_URL       "url"
  84 #define CURL_BLOCK_OPT_READAHEAD "readahead"
  85 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
  86 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
  87 #define CURL_BLOCK_OPT_COOKIE    "cookie"
  88 #define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
  89 #define CURL_BLOCK_OPT_USERNAME "username"
  90 #define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
  91 #define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
  92 #define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
  93
  94 struct BDRVCURLState;
  95
  96 typedef struct CURLAIOCB {
  97     BlockAIOCB common;
  98     QEMUIOVector *qiov;
  99
 100     int64_t sector_num;
 101     int nb_sectors;
 102
 103     size_t start;
 104     size_t end;
 105 } CURLAIOCB;
 106
 107 typedef struct CURLSocket {
 108     int fd;
 109     QLIST_ENTRY(CURLSocket) next;
 110 } CURLSocket;
 111
 112 typedef struct CURLState
 113 {
 114     struct BDRVCURLState *s;
 115     CURLAIOCB *acb[CURL_NUM_ACB];
 116     CURL *curl;
 117     QLIST_HEAD(, CURLSocket) sockets;
 118     char *orig_buf;
 119     size_t buf_start;
 120     size_t buf_off;
 121     size_t buf_len;
 122     char range[128];
 123     char errmsg[CURL_ERROR_SIZE];
 124     char in_use;
 125 } CURLState;
 126
 127 typedef struct BDRVCURLState {
 128     CURLM *multi;
 129     QEMUTimer timer;
 130     size_t len;
 131     CURLState states[CURL_NUM_STATES];
 132     char *url;
 133     size_t readahead_size;
 134     bool sslverify;
 135     uint64_t timeout;
 136     char *cookie;
 137     bool accept_range;
 138     AioContext *aio_context;
 139     QemuMutex mutex;
 140     char *username;
 141     char *password;
 142     char *proxyusername;
 143     char *proxypassword;
 144 } BDRVCURLState;
 145
 146 static void curl_clean_state(CURLState *s);
 147 static void curl_multi_do(void *arg);
 148 static void curl_multi_read(void *arg);
 149
 150 #ifdef NEED_CURL_TIMER_CALLBACK
 151 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 152 {
 153     BDRVCURLState *s = opaque;
 154
 155     DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms);
 156     if (timeout_ms == -1) {
 157         timer_del(&s->timer);
 158     } else {
 159         int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000;
 160         timer_mod(&s->timer,
 161                   qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns);
 162     }
 163     return 0;
 164 }
 165 #endif
 166
 167 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
 168                         void *userp, void *sp)
 169 {
 170     BDRVCURLState *s;
 171     CURLState *state = NULL;
 172     CURLSocket *socket;
 173
 174     curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
 175     s = state->s;
 176
 177     QLIST_FOREACH(socket, &state->sockets, next) {
 178         if (socket->fd == fd) {
 179             if (action == CURL_POLL_REMOVE) {
 180                 QLIST_REMOVE(socket, next);
 181                 g_free(socket);
 182             }
 183             break;
 184         }
 185     }
 186     if (!socket) {
 187         socket = g_new0(CURLSocket, 1);
 188         socket->fd = fd;
 189         QLIST_INSERT_HEAD(&state->sockets, socket, next);
 190     }
 191     socket = NULL;
 192
 193     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, (int)fd);
 194     switch (action) {
 195         case CURL_POLL_IN:
 196             aio_set_fd_handler(s->aio_context, fd, false,
 197                                curl_multi_read, NULL, NULL, state);
 198             break;
 199         case CURL_POLL_OUT:
 200             aio_set_fd_handler(s->aio_context, fd, false,
 201                                NULL, curl_multi_do, NULL, state);
 202             break;
 203         case CURL_POLL_INOUT:
 204             aio_set_fd_handler(s->aio_context, fd, false,
 205                                curl_multi_read, curl_multi_do, NULL, state);
 206             break;
 207         case CURL_POLL_REMOVE:
 208             aio_set_fd_handler(s->aio_context, fd, false,
 209                                NULL, NULL, NULL, NULL);
 210             break;
 211     }
 212
 213     return 0;
 214 }
 215
 216 static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 217 {
 218     BDRVCURLState *s = opaque;
 219     size_t realsize = size * nmemb;
 220     const char *accept_line = "Accept-Ranges: bytes";
 221
 222     if (realsize >= strlen(accept_line)
 223         && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) {
 224         s->accept_range = true;
 225     }
 226
 227     return realsize;
 228 }
 229
 230 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
 231 {
 232     CURLState *s = ((CURLState*)opaque);
 233     size_t realsize = size * nmemb;
 234     int i;
 235
 236     DPRINTF("CURL: Just reading %zd bytes\n", realsize);
 237
 238     if (!s || !s->orig_buf) {
 239         goto read_end;
 240     }
 241
 242     if (s->buf_off >= s->buf_len) {
 243         /* buffer full, read nothing */
 244         goto read_end;
 245     }
 246     realsize = MIN(realsize, s->buf_len - s->buf_off);
 247     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
 248     s->buf_off += realsize;
 249
 250     for(i=0; i<CURL_NUM_ACB; i++) {
 251         CURLAIOCB *acb = s->acb[i];
 252
 253         if (!acb)
 254             continue;
 255
 256         if ((s->buf_off >= acb->end)) {
 257             size_t request_length = acb->nb_sectors * BDRV_SECTOR_SIZE;
 258
 259             qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
 260                                 acb->end - acb->start);
 261
 262             if (acb->end - acb->start < request_length) {
 263                 size_t offset = acb->end - acb->start;
 264                 qemu_iovec_memset(acb->qiov, offset, 0,
 265                                   request_length - offset);
 266             }
 267
 268             acb->common.cb(acb->common.opaque, 0);
 269             qemu_aio_unref(acb);
 270             s->acb[i] = NULL;
 271         }
 272     }
 273
 274 read_end:
 275     /* curl will error out if we do not return this value */
 276     return size * nmemb;
 277 }
 278
 279 static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len,
 280                          CURLAIOCB *acb)
 281 {
 282     int i;
 283     size_t end = start + len;
 284     size_t clamped_end = MIN(end, s->len);
 285     size_t clamped_len = clamped_end - start;
 286
 287     for (i=0; i<CURL_NUM_STATES; i++) {
 288         CURLState *state = &s->states[i];
 289         size_t buf_end = (state->buf_start + state->buf_off);
 290         size_t buf_fend = (state->buf_start + state->buf_len);
 291
 292         if (!state->orig_buf)
 293             continue;
 294         if (!state->buf_off)
 295             continue;
 296
 297         // Does the existing buffer cover our section?
 298         if ((start >= state->buf_start) &&
 299             (start <= buf_end) &&
 300             (clamped_end >= state->buf_start) &&
 301             (clamped_end <= buf_end))
 302         {
 303             char *buf = state->orig_buf + (start - state->buf_start);
 304
 305             qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
 306             if (clamped_len < len) {
 307                 qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
 308             }
 309             acb->common.cb(acb->common.opaque, 0);
 310
 311             return FIND_RET_OK;
 312         }
 313
 314         // Wait for unfinished chunks
 315         if (state->in_use &&
 316             (start >= state->buf_start) &&
 317             (start <= buf_fend) &&
 318             (clamped_end >= state->buf_start) &&
 319             (clamped_end <= buf_fend))
 320         {
 321             int j;
 322
 323             acb->start = start - state->buf_start;
 324             acb->end = acb->start + clamped_len;
 325
 326             for (j=0; j<CURL_NUM_ACB; j++) {
 327                 if (!state->acb[j]) {
 328                     state->acb[j] = acb;
 329                     return FIND_RET_WAIT;
 330                 }
 331             }
 332         }
 333     }
 334
 335     return FIND_RET_NONE;
 336 }
 337
 338 /* Called with s->mutex held.  */
 339 static void curl_multi_check_completion(BDRVCURLState *s)
 340 {
 341     int msgs_in_queue;
 342
 343     /* Try to find done transfers, so we can free the easy
 344      * handle again. */
 345     for (;;) {
 346         CURLMsg *msg;
 347         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
 348
 349         /* Quit when there are no more completions */
 350         if (!msg)
 351             break;
 352
 353         if (msg->msg == CURLMSG_DONE) {
 354             CURLState *state = NULL;
 355             curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
 356                               (char **)&state);
 357
 358             /* ACBs for successful messages get completed in curl_read_cb */
 359             if (msg->data.result != CURLE_OK) {
 360                 int i;
 361                 static int errcount = 100;
 362
 363                 /* Don't lose the original error message from curl, since
 364                  * it contains extra data.
 365                  */
 366                 if (errcount > 0) {
 367                     error_report("curl: %s", state->errmsg);
 368                     if (--errcount == 0) {
 369                         error_report("curl: further errors suppressed");
 370                     }
 371                 }
 372
 373                 for (i = 0; i < CURL_NUM_ACB; i++) {
 374                     CURLAIOCB *acb = state->acb[i];
 375
 376                     if (acb == NULL) {
 377                         continue;
 378                     }
 379
 380                     qemu_mutex_unlock(&s->mutex);
 381                     acb->common.cb(acb->common.opaque, -EIO);
 382                     qemu_mutex_lock(&s->mutex);
 383                     qemu_aio_unref(acb);
 384                     state->acb[i] = NULL;
 385                 }
 386             }
 387
 388             curl_clean_state(state);
 389             break;
 390         }
 391     }
 392 }
 393
 394 /* Called with s->mutex held.  */
 395 static void curl_multi_do_locked(CURLState *s)
 396 {
 397     CURLSocket *socket, *next_socket;
 398     int running;
 399     int r;
 400
 401     if (!s->s->multi) {
 402         return;
 403     }
 404
 405     /* Need to use _SAFE because curl_multi_socket_action() may trigger
 406      * curl_sock_cb() which might modify this list */
 407     QLIST_FOREACH_SAFE(socket, &s->sockets, next, next_socket) {
 408         do {
 409             r = curl_multi_socket_action(s->s->multi, socket->fd, 0, &running);
 410         } while (r == CURLM_CALL_MULTI_PERFORM);
 411     }
 412 }
 413
 414 static void curl_multi_do(void *arg)
 415 {
 416     CURLState *s = (CURLState *)arg;
 417
 418     qemu_mutex_lock(&s->s->mutex);
 419     curl_multi_do_locked(s);
 420     qemu_mutex_unlock(&s->s->mutex);
 421 }
 422
 423 static void curl_multi_read(void *arg)
 424 {
 425     CURLState *s = (CURLState *)arg;
 426
 427     qemu_mutex_lock(&s->s->mutex);
 428     curl_multi_do_locked(s);
 429     curl_multi_check_completion(s->s);
 430     qemu_mutex_unlock(&s->s->mutex);
 431 }
 432
 433 static void curl_multi_timeout_do(void *arg)
 434 {
 435 #ifdef NEED_CURL_TIMER_CALLBACK
 436     BDRVCURLState *s = (BDRVCURLState *)arg;
 437     int running;
 438
 439     if (!s->multi) {
 440         return;
 441     }
 442
 443     qemu_mutex_lock(&s->mutex);
 444     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 445
 446     curl_multi_check_completion(s);
 447     qemu_mutex_unlock(&s->mutex);
 448 #else
 449     abort();
 450 #endif
 451 }
 452
 453 static CURLState *curl_init_state(BlockDriverState *bs, BDRVCURLState *s)
 454 {
 455     CURLState *state = NULL;
 456     int i, j;
 457
 458     do {
 459         for (i=0; i<CURL_NUM_STATES; i++) {
 460             for (j=0; j<CURL_NUM_ACB; j++)
 461                 if (s->states[i].acb[j])
 462                     continue;
 463             if (s->states[i].in_use)
 464                 continue;
 465
 466             state = &s->states[i];
 467             state->in_use = 1;
 468             break;
 469         }
 470         if (!state) {
 471             aio_poll(bdrv_get_aio_context(bs), true);
 472         }
 473     } while(!state);
 474
 475     if (!state->curl) {
 476         state->curl = curl_easy_init();
 477         if (!state->curl) {
 478             return NULL;
 479         }
 480         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
 481         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
 482                          (long) s->sslverify);
 483         if (s->cookie) {
 484             curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
 485         }
 486         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, (long)s->timeout);
 487         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
 488                          (void *)curl_read_cb);
 489         curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
 490         curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
 491         curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
 492         curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
 493         curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
 494         curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
 495         curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1);
 496
 497         if (s->username) {
 498             curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
 499         }
 500         if (s->password) {
 501             curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
 502         }
 503         if (s->proxyusername) {
 504             curl_easy_setopt(state->curl,
 505                              CURLOPT_PROXYUSERNAME, s->proxyusername);
 506         }
 507         if (s->proxypassword) {
 508             curl_easy_setopt(state->curl,
 509                              CURLOPT_PROXYPASSWORD, s->proxypassword);
 510         }
 511
 512         /* Restrict supported protocols to avoid security issues in the more
 513          * obscure protocols.  For example, do not allow POP3/SMTP/IMAP see
 514          * CVE-2013-0249.
 515          *
 516          * Restricting protocols is only supported from 7.19.4 upwards.
 517          */
 518 #if LIBCURL_VERSION_NUM >= 0x071304
 519         curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS);
 520         curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS);
 521 #endif
 522
 523 #ifdef DEBUG_VERBOSE
 524         curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
 525 #endif
 526     }
 527
 528     QLIST_INIT(&state->sockets);
 529     state->s = s;
 530
 531     return state;
 532 }
 533
 534 static void curl_clean_state(CURLState *s)
 535 {
 536     int j;
 537     for (j = 0; j < CURL_NUM_ACB; j++) {
 538         assert(!s->acb[j]);
 539     }
 540
 541     if (s->s->multi)
 542         curl_multi_remove_handle(s->s->multi, s->curl);
 543
 544     while (!QLIST_EMPTY(&s->sockets)) {
 545         CURLSocket *socket = QLIST_FIRST(&s->sockets);
 546
 547         QLIST_REMOVE(socket, next);
 548         g_free(socket);
 549     }
 550
 551     s->in_use = 0;
 552 }
 553
 554 static void curl_parse_filename(const char *filename, QDict *options,
 555                                 Error **errp)
 556 {
 557     qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
 558 }
 559
 560 static void curl_detach_aio_context(BlockDriverState *bs)
 561 {
 562     BDRVCURLState *s = bs->opaque;
 563     int i;
 564
 565     for (i = 0; i < CURL_NUM_STATES; i++) {
 566         if (s->states[i].in_use) {
 567             curl_clean_state(&s->states[i]);
 568         }
 569         if (s->states[i].curl) {
 570             curl_easy_cleanup(s->states[i].curl);
 571             s->states[i].curl = NULL;
 572         }
 573         g_free(s->states[i].orig_buf);
 574         s->states[i].orig_buf = NULL;
 575     }
 576     if (s->multi) {
 577         curl_multi_cleanup(s->multi);
 578         s->multi = NULL;
 579     }
 580
 581     timer_del(&s->timer);
 582 }
 583
 584 static void curl_attach_aio_context(BlockDriverState *bs,
 585                                     AioContext *new_context)
 586 {
 587     BDRVCURLState *s = bs->opaque;
 588
 589     aio_timer_init(new_context, &s->timer,
 590                    QEMU_CLOCK_REALTIME, SCALE_NS,
 591                    curl_multi_timeout_do, s);
 592
 593     assert(!s->multi);
 594     s->multi = curl_multi_init();
 595     s->aio_context = new_context;
 596     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
 597 #ifdef NEED_CURL_TIMER_CALLBACK
 598     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
 599     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
 600 #endif
 601 }
 602
 603 static QemuOptsList runtime_opts = {
 604     .name = "curl",
 605     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 606     .desc = {
 607         {
 608             .name = CURL_BLOCK_OPT_URL,
 609             .type = QEMU_OPT_STRING,
 610             .help = "URL to open",
 611         },
 612         {
 613             .name = CURL_BLOCK_OPT_READAHEAD,
 614             .type = QEMU_OPT_SIZE,
 615             .help = "Readahead size",
 616         },
 617         {
 618             .name = CURL_BLOCK_OPT_SSLVERIFY,
 619             .type = QEMU_OPT_BOOL,
 620             .help = "Verify SSL certificate"
 621         },
 622         {
 623             .name = CURL_BLOCK_OPT_TIMEOUT,
 624             .type = QEMU_OPT_NUMBER,
 625             .help = "Curl timeout"
 626         },
 627         {
 628             .name = CURL_BLOCK_OPT_COOKIE,
 629             .type = QEMU_OPT_STRING,
 630             .help = "Pass the cookie or list of cookies with each request"
 631         },
 632         {
 633             .name = CURL_BLOCK_OPT_COOKIE_SECRET,
 634             .type = QEMU_OPT_STRING,
 635             .help = "ID of secret used as cookie passed with each request"
 636         },
 637         {
 638             .name = CURL_BLOCK_OPT_USERNAME,
 639             .type = QEMU_OPT_STRING,
 640             .help = "Username for HTTP auth"
 641         },
 642         {
 643             .name = CURL_BLOCK_OPT_PASSWORD_SECRET,
 644             .type = QEMU_OPT_STRING,
 645             .help = "ID of secret used as password for HTTP auth",
 646         },
 647         {
 648             .name = CURL_BLOCK_OPT_PROXY_USERNAME,
 649             .type = QEMU_OPT_STRING,
 650             .help = "Username for HTTP proxy auth"
 651         },
 652         {
 653             .name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
 654             .type = QEMU_OPT_STRING,
 655             .help = "ID of secret used as password for HTTP proxy auth",
 656         },
 657         { /* end of list */ }
 658     },
 659 };
 660
 661
 662 static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 663                      Error **errp)
 664 {
 665     BDRVCURLState *s = bs->opaque;
 666     CURLState *state = NULL;
 667     QemuOpts *opts;
 668     Error *local_err = NULL;
 669     const char *file;
 670     const char *cookie;
 671     const char *cookie_secret;
 672     double d;
 673     const char *secretid;
 674     const char *protocol_delimiter;
 675
 676     static int inited = 0;
 677
 678     if (flags & BDRV_O_RDWR) {
 679         error_setg(errp, "curl block device does not support writes");
 680         return -EROFS;
 681     }
 682
 683     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 684     qemu_opts_absorb_qdict(opts, options, &local_err);
 685     if (local_err) {
 686         error_propagate(errp, local_err);
 687         goto out_noclean;
 688     }
 689
 690     s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
 691                                           READ_AHEAD_DEFAULT);
 692     if ((s->readahead_size & 0x1ff) != 0) {
 693         error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512",
 694                    s->readahead_size);
 695         goto out_noclean;
 696     }
 697
 698     s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT,
 699                                      CURL_TIMEOUT_DEFAULT);
 700     if (s->timeout > CURL_TIMEOUT_MAX) {
 701         error_setg(errp, "timeout parameter is too large or negative");
 702         goto out_noclean;
 703     }
 704
 705     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
 706
 707     cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
 708     cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
 709
 710     if (cookie && cookie_secret) {
 711         error_setg(errp,
 712                    "curl driver cannot handle both cookie and cookie secret");
 713         goto out_noclean;
 714     }
 715
 716     if (cookie_secret) {
 717         s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
 718         if (!s->cookie) {
 719             goto out_noclean;
 720         }
 721     } else {
 722         s->cookie = g_strdup(cookie);
 723     }
 724
 725     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
 726     if (file == NULL) {
 727         error_setg(errp, "curl block driver requires an 'url' option");
 728         goto out_noclean;
 729     }
 730
 731     if (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
 732         !strstart(protocol_delimiter, "://", NULL))
 733     {
 734         error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
 735                    "start with '%s://')", bs->drv->protocol_name, file,
 736                    bs->drv->protocol_name);
 737         goto out_noclean;
 738     }
 739
 740     s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
 741     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
 742
 743     if (secretid) {
 744         s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
 745         if (!s->password) {
 746             goto out_noclean;
 747         }
 748     }
 749
 750     s->proxyusername = g_strdup(
 751         qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
 752     secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
 753     if (secretid) {
 754         s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
 755         if (!s->proxypassword) {
 756             goto out_noclean;
 757         }
 758     }
 759
 760     if (!inited) {
 761         curl_global_init(CURL_GLOBAL_ALL);
 762         inited = 1;
 763     }
 764
 765     DPRINTF("CURL: Opening %s\n", file);
 766     s->aio_context = bdrv_get_aio_context(bs);
 767     s->url = g_strdup(file);
 768     state = curl_init_state(bs, s);
 769     if (!state)
 770         goto out_noclean;
 771
 772     // Get file size
 773
 774     s->accept_range = false;
 775     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
 776     curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION,
 777                      curl_header_cb);
 778     curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s);
 779     if (curl_easy_perform(state->curl))
 780         goto out;
 781     if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
 782         goto out;
 783     }
 784     /* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
 785      * know or the size is zero. From 7.19.4 CURL returns -1 if size is not
 786      * known and zero if it is realy zero-length file. */
 787 #if LIBCURL_VERSION_NUM >= 0x071304
 788     if (d < 0) {
 789         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 790                 "Server didn't report file size.");
 791         goto out;
 792     }
 793 #else
 794     if (d <= 0) {
 795         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 796                 "Unknown file size or zero-length file.");
 797         goto out;
 798     }
 799 #endif
 800
 801     s->len = (size_t)d;
 802
 803     if ((!strncasecmp(s->url, "http://", strlen("http://"))
 804         || !strncasecmp(s->url, "https://", strlen("https://")))
 805         && !s->accept_range) {
 806         pstrcpy(state->errmsg, CURL_ERROR_SIZE,
 807                 "Server does not support 'range' (byte ranges).");
 808         goto out;
 809     }
 810     DPRINTF("CURL: Size = %zd\n", s->len);
 811
 812     curl_clean_state(state);
 813     curl_easy_cleanup(state->curl);
 814     state->curl = NULL;
 815
 816     qemu_mutex_init(&s->mutex);
 817     curl_attach_aio_context(bs, bdrv_get_aio_context(bs));
 818
 819     qemu_opts_del(opts);
 820     return 0;
 821
 822 out:
 823     error_setg(errp, "CURL: Error opening file: %s", state->errmsg);
 824     curl_easy_cleanup(state->curl);
 825     state->curl = NULL;
 826 out_noclean:
 827     g_free(s->cookie);
 828     g_free(s->url);
 829     qemu_opts_del(opts);
 830     return -EINVAL;
 831 }
 832
 833 static const AIOCBInfo curl_aiocb_info = {
 834     .aiocb_size         = sizeof(CURLAIOCB),
 835 };
 836
 837
 838 static void curl_readv_bh_cb(void *p)
 839 {
 840     CURLState *state;
 841     int running;
 842     int ret = -EINPROGRESS;
 843
 844     CURLAIOCB *acb = p;
 845     BlockDriverState *bs = acb->common.bs;
 846     BDRVCURLState *s = bs->opaque;
 847
 848     size_t start = acb->sector_num * BDRV_SECTOR_SIZE;
 849     size_t end;
 850
 851     qemu_mutex_lock(&s->mutex);
 852
 853     // In case we have the requested data already (e.g. read-ahead),
 854     // we can just call the callback and be done.
 855     switch (curl_find_buf(s, start, acb->nb_sectors * BDRV_SECTOR_SIZE, acb)) {
 856         case FIND_RET_OK:
 857             qemu_aio_unref(acb);
 858             // fall through
 859         case FIND_RET_WAIT:
 860             goto out;
 861         default:
 862             break;
 863     }
 864
 865     // No cache found, so let's start a new request
 866     state = curl_init_state(acb->common.bs, s);
 867     if (!state) {
 868         ret = -EIO;
 869         goto out;
 870     }
 871
 872     acb->start = 0;
 873     acb->end = MIN(acb->nb_sectors * BDRV_SECTOR_SIZE, s->len - start);
 874
 875     state->buf_off = 0;
 876     g_free(state->orig_buf);
 877     state->buf_start = start;
 878     state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
 879     end = start + state->buf_len - 1;
 880     state->orig_buf = g_try_malloc(state->buf_len);
 881     if (state->buf_len && state->orig_buf == NULL) {
 882         curl_clean_state(state);
 883         ret = -ENOMEM;
 884         goto out;
 885     }
 886     state->acb[0] = acb;
 887
 888     snprintf(state->range, 127, "%zd-%zd", start, end);
 889     DPRINTF("CURL (AIO): Reading %llu at %zd (%s)\n",
 890             (acb->nb_sectors * BDRV_SECTOR_SIZE), start, state->range);
 891     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
 892
 893     curl_multi_add_handle(s->multi, state->curl);
 894
 895     /* Tell curl it needs to kick things off */
 896     curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
 897
 898 out:
 899     qemu_mutex_unlock(&s->mutex);
 900     if (ret != -EINPROGRESS) {
 901         acb->common.cb(acb->common.opaque, ret);
 902         qemu_aio_unref(acb);
 903     }
 904 }
 905
 906 static BlockAIOCB *curl_aio_readv(BlockDriverState *bs,
 907         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 908         BlockCompletionFunc *cb, void *opaque)
 909 {
 910     CURLAIOCB *acb;
 911
 912     acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque);
 913
 914     acb->qiov = qiov;
 915     acb->sector_num = sector_num;
 916     acb->nb_sectors = nb_sectors;
 917
 918     aio_bh_schedule_oneshot(bdrv_get_aio_context(bs), curl_readv_bh_cb, acb);
 919     return &acb->common;
 920 }
 921
 922 static void curl_close(BlockDriverState *bs)
 923 {
 924     BDRVCURLState *s = bs->opaque;
 925
 926     DPRINTF("CURL: Close\n");
 927     curl_detach_aio_context(bs);
 928     qemu_mutex_destroy(&s->mutex);
 929
 930     g_free(s->cookie);
 931     g_free(s->url);
 932 }
 933
 934 static int64_t curl_getlength(BlockDriverState *bs)
 935 {
 936     BDRVCURLState *s = bs->opaque;
 937     return s->len;
 938 }
 939
 940 static BlockDriver bdrv_http = {
 941     .format_name                = "http",
 942     .protocol_name              = "http",
 943
 944     .instance_size              = sizeof(BDRVCURLState),
 945     .bdrv_parse_filename        = curl_parse_filename,
 946     .bdrv_file_open             = curl_open,
 947     .bdrv_close                 = curl_close,
 948     .bdrv_getlength             = curl_getlength,
 949
 950     .bdrv_aio_readv             = curl_aio_readv,
 951
 952     .bdrv_detach_aio_context    = curl_detach_aio_context,
 953     .bdrv_attach_aio_context    = curl_attach_aio_context,
 954 };
 955
 956 static BlockDriver bdrv_https = {
 957     .format_name                = "https",
 958     .protocol_name              = "https",
 959
 960     .instance_size              = sizeof(BDRVCURLState),
 961     .bdrv_parse_filename        = curl_parse_filename,
 962     .bdrv_file_open             = curl_open,
 963     .bdrv_close                 = curl_close,
 964     .bdrv_getlength             = curl_getlength,
 965
 966     .bdrv_aio_readv             = curl_aio_readv,
 967
 968     .bdrv_detach_aio_context    = curl_detach_aio_context,
 969     .bdrv_attach_aio_context    = curl_attach_aio_context,
 970 };
 971
 972 static BlockDriver bdrv_ftp = {
 973     .format_name                = "ftp",
 974     .protocol_name              = "ftp",
 975
 976     .instance_size              = sizeof(BDRVCURLState),
 977     .bdrv_parse_filename        = curl_parse_filename,
 978     .bdrv_file_open             = curl_open,
 979     .bdrv_close                 = curl_close,
 980     .bdrv_getlength             = curl_getlength,
 981
 982     .bdrv_aio_readv             = curl_aio_readv,
 983
 984     .bdrv_detach_aio_context    = curl_detach_aio_context,
 985     .bdrv_attach_aio_context    = curl_attach_aio_context,
 986 };
 987
 988 static BlockDriver bdrv_ftps = {
 989     .format_name                = "ftps",
 990     .protocol_name              = "ftps",
 991
 992     .instance_size              = sizeof(BDRVCURLState),
 993     .bdrv_parse_filename        = curl_parse_filename,
 994     .bdrv_file_open             = curl_open,
 995     .bdrv_close                 = curl_close,
 996     .bdrv_getlength             = curl_getlength,
 997
 998     .bdrv_aio_readv             = curl_aio_readv,
 999
1000     .bdrv_detach_aio_context    = curl_detach_aio_context,
1001     .bdrv_attach_aio_context    = curl_attach_aio_context,
1002 };
1003
1004 static void curl_block_init(void)
1005 {
1006     bdrv_register(&bdrv_http);
1007     bdrv_register(&bdrv_https);
1008     bdrv_register(&bdrv_ftp);
1009     bdrv_register(&bdrv_ftps);
1010 }
1011
1012 block_init(curl_block_init);